Refurb near Cambridge

[LinearPancakes]

Hi folks,

 

We're starting a refurb of our home soon, and I've increasingly been coming across interesting discussions buildhub.

 

Looking to go beyond building regs for extended areas in terms of insulation & air tightness, and go for MVHR & ASHP. Going all in on led smart lighting.

 

Looking forward to discussions!

[Marvin]

Welcome to Buildhub. @LinearPancakes

 

It worth considering all the AIM APE elements before making decisions. That is Airtightness, Insulation, Mechanical Ventilation with Heat Recovery,  and Air Source Heat Pump, Photovoltaics and Electric Vehicle.

 

Some of these will not work properly without the others:

 

1. A MVHR will not work properly without Airtightness.
2. An Air Source Heat Pump will have to compensate for the lack of Airtightness and Insulation to the degree that the benefits become questionable, especially during winter, without them.
3. An ASHP uses electricity and Photovoltaics can supply a little during winter and a lot during summer when cooling can be a problem and an ASHP can supply cooling.
4. PV can supply a little to an Electric Vehicle during winter and plenty during summer if your vehicle is at home during sunny days.

So if finances cause you to have to consider only a few in my humble opinion AIM first and go APE later.

 

Good luck with your project and remember the only daft question is the one you didn't ask and don't expect a good answer to your question unless you supply enough information.

 

M

 

[Nickfromwales]

Agree with the above 100%, but it’s almost pointless going crazy in the extension and having that bolted to a draughty bag-o-carp   

 

You can have huge amounts of insulation ( to help with fabric heat loss ) but that will mean nothing without airtightness ( to help with ventilation heat loss ). 
 

With very good detailing eg attention to / knowledge of airtightness, you can then integrate an MVHR system, to recover otherwise lost heat from the infiltration. Infiltration can be from deliberate sources rather than missed opportunity, so be aware that a regular BRegs build would mandate trickle vents if you go airtight aka ‘draught proof’ beyond a certain ACH score. 
 

Also, you cannot just fit MVHR to the “good half” of a house  

 

MVHR will be one of the biggest rewards if you put the effort in, more so than just putting loads of insulation everywhere.

[Marvin]

50 minutes ago, Nickfromwales said:

Agree with the above 100%, but it’s almost pointless going crazy in the extension and having that bolted to a draughty bag-o-carp   

 

You can have huge amounts of insulation ( to help with fabric heat loss ) but that will mean nothing without airtightness ( to help with ventilation heat loss ). 
 

With very good detailing eg attention to / knowledge of airtightness, you can then integrate an MVHR system, to recover otherwise lost heat from the infiltration. Infiltration can be from deliberate sources rather than missed opportunity, so be aware that a regular BRegs build would mandate trickle vents if you go airtight aka ‘draught proof’ beyond a certain ACH score. 
 

Also, you cannot just fit MVHR to the “good half” of a house  

 

MVHR will be one of the biggest rewards if you put the effort in, more so than just putting loads of insulation everywhere.

I completely agree. Couldn't say it better!

Knowing this sort of information before starting out can save you masses of disappointment later!

 

[LinearPancakes]

Many thanks @Marvin & @Nickfromwales. I'll have to try to remember AIM APE. ? Unfortunately our roof is quite shaded so I'm not sure solar panels are an option for us.

 

Certainly going to try to bring the existing house in line as much as possible. The new triple glazed windows will be throughout, without trickle vents, and we'll be making sure to tape the frames to the airtightness layer. I'm expecting quite a lot of work getting things and keeping things airtight enough, esp. given it's a refurb not a new build.

 

A little apprehensive, but looking forward to learning from it.